I use these guys often for rentals. http://www.grandstage.com/images/pdf/RentalCatalog_PRINT.pdf
I don't rent from them, but they're pretty decent also http://www.thelightingconnection.com/
Ship probably can get them for you as well.
Neither one delivers. If you need a local liaison who has contacts with a lot of people in the business in Chicago give me a call.